For many years, the most common type of trailer hitch has been the ball hitch, a ball mounted at or near the rear bumper of a towing vehicle for receipt within a cooperating socket mounted at or near a forward end of a trailer. These hitches have acquired popularity due to their simplicity, and due to the universal movement which is possible when using a ball hitch. It will be appreciated, for example, that such hitches typically accommodate pivot about orthogonal axes, due at least in part to the spherical nature of conventional ball mounts.
Recently, however, fifth wheel hitches have gained popularity due to a perceived improvement to towing safety, based on the position and style of the hitch. Fifth wheel hitches, it will be understood, employ a kingpin which is secured to a gooseneck trailer for receipt in a fifth wheel hitch socket assembly mounted on the towing vehicle (typically, in the bed of a pick-up truck). The fifth wheel hitch socket assembly is adapted to selectively grip the kingpin, generally via clamping structure which closes around a groove in the kingpin. Accordingly, although the kingpin generally does allow side-to-side pivot of the trailer, it restricts the type of universal movement possible with most ball hitches. These hitches also typically employ protruding clamping structure which may interfere with normal vehicle use. Fifth wheel hitches thus have heretofore fallen short of consumer expectations.
In an attempt to further improve utility, hitch makers have once again tuned to the basic concept embodied by ball hitches, but with the certain adaptations intended to employ advantages provided by fifth wheel hitches. Accordingly, ball hitches have been adapted for improved mounting, typically by mounting the hitch in the bed of a tuck such that a gooseneck trailer may be used. Such ball hitches are described, for example, in U.S. Pat. No. 5,435,585 to James W. Chambers, and in U.S. Pat. No. 5,571,270 to Kenneth M. Larkin, both of which are subject to common ownership herewith. The disclosures of these patents are incorporated herein by this reference.
Unfortunately, most gooseneck trailers are fitted with a kingpin for use in connection with a fifth wheel receiver, and thus are not suited for use in connection to a towing vehicle which employs a ball mount. Although makeshift adapters have been proposed for use in converting a ball mount into a fifth wheel receiver, such adapters typically involve complicated structure which detracts from the very benefits the ball hitch is intended to provide. What is needed is a hitch adapter which is configured for use in readily coupling a kingpin-type trailer with a towing vehicle which employs a ball mount. It would be further desirable for such adapter to accommodate the type of universal movement common to ball hitches without detracting from stability or stowability of the hitch.